An Investigation for 2-stage Injection Strategy on Combustion and Emissions in a D.I Compression-ignition Engine Fueled with DME

This work was investigated 2-stage injection strategy on combustion and emissions in a direct injection compression-ignition engine fueled with DME. Single cylinder engine was equipped with common rail. Injection pressure was 700bar, dSOI between the main injection and the pilot injection was varied. Diesel was used as compared fuel of DME in all cases. The results was shown that maximum pressure was higher than all cases and its amount of DME and diesel was similar. Regardless the pilot injection, the main fuel injection timing was same. The heat release rate of the main injection for diesel was high while that of pilot injection for DME was high. The THC was very low regardless of the fuel type and injection strategy. In the single injection, NOx was increased to retard of main injection timing regardless of the fuel type. NOx emissions was decreased with the retardation of the main injection timing regardless of the fuel type in the case of 2-stage injection strategy.